The teacher's guides for Connected Mathematics measure 8.5" by 11". Below is a photograph of a middle school teacher holding a teacher's guide.
A. Use the photograph to figure out how tall the teacher is. Explain your procedure.
Ans. Book's length in picture = 1.6 cm
Actual length = 11"
Teacher's height in picture = 11 cm
11 รท 1.6 = 6.875 ( ratio from book to teacher in the picture)
11" x 6.875 = 75.675 / 12 = 6.3 feet - 1.6/11 = 11 / x
I found the ratio in the picture and then replaced it with the real value which is the height of the book
The scale factor from image to reality = 15.71, and if you round it up you get 16.
B. How do you think the police determined the height of the robber?
Ans. The police probably found the robber's height by comparing the an object ( with known dimensions ) to the robber in the picture. I think they most probably used the method I used in part A.
Follow-Up
1. Estimate the height of the door in the photograph
Height of the book in the picture- 1.6 cm
Height of the door in the picture- 5.6 cm
5.6 / 1.6 = x / 11" ( 11" is actual height of the book)
5.6 / 1.6- 5.6 times 11" = x
x = height of the door = 3.5 times 11" = 38.5" = 3.2 ft
2. Do you think your estimate in question 1 is an underestimate or an over estimate? Why?
I think the the estimate shown is an underestimate, as in the picture, the door is actually much behind the book. This makes the door appear smaller.
29/10/08
Block-C
4.1 & F.U.
No notes
The teacher's guides for Connected Mathematics measure 8.5" by 11". Below is a photograph of a middle school teacher holding a teacher's guide.
A. Use the photograph to figure out how tall the teacher is. Explain your procedure.
Ans. Book's length in picture = 1.6 cm
Actual length = 11"
Teacher's height in picture = 11 cm
11 รท 1.6 = 6.875 ( ratio from book to teacher in the picture)
11" x 6.875 = 75.675 / 12 = 6.3 feet - 1.6/11 = 11 / x
I found the ratio in the picture and then replaced it with the real value which is the height of the book
The scale factor from image to reality = 15.71, and if you round it up you get 16.
B. How do you think the police determined the height of the robber?
Ans. The police probably found the robber's height by comparing the an object ( with known dimensions ) to the robber in the picture. I think they most probably used the method I used in part A.
Follow-Up
1. Estimate the height of the door in the photograph
Height of the book in the picture- 1.6 cm
Height of the door in the picture- 5.6 cm
5.6 / 1.6 = x / 11" ( 11" is actual height of the book)
5.6 / 1.6- 5.6 times 11" = x
x = height of the door = 3.5 times 11" = 38.5" = 3.2 ft
2. Do you think your estimate in question 1 is an underestimate or an over estimate? Why?
I think the the estimate shown is an underestimate, as in the picture, the door is actually much behind the book. This makes the door appear smaller.